Various surgical tools are available for coagulation or cauterization of tissue. The general, prior art designs include a set of electrodes to which a current is applied. In a monopolar configuration, one electrode is placed against the tissue of interest and the current is returned at a distant electrode. In a bipolar configuration, two local electrodes are placed against the tissue of interest and the current flows between the two electrodes.
Referring to FIG. 1, prior art cautery devices generally require a set of wire frame electrodes at the tip. Cautery probe 101 includes electrode 102 and electrode 103 which are insulated so that electrode 102 and electrode 103 are not in electrical contact.
Referring to FIG. 2, switching for a prior art cautery device is shown. Coagulation current source 204 is connected at a first electric potential to switch 205 which is further connected by a conductor 207 to electrode 102. Coagulation current source 204 is connected at a second electric potential to switch 206 which is further connected by a conductor 209 to electrode 103. Switch 205 and switch 206 are SPST (single pole single throw) normally-open switches.
In operation, the prior art cautery device is placed in contact with tissue. Switch 205 and switch 206 are then closed to energize an electric potential difference between electrode 102 and electrode 103. The electric potential difference initiates a current flow from electrode 102 to electrode 103 through the tissue.
U.S. Pat. No. 6,109,268 to Thapliyal et al. discloses an electrosurgical probe that has a tip region which comprises electrode terminals designed to deliver electrical energy in the vicinity of the tip. The return electrodes may comprise a single tubular member of conductive material proximal to the electrode terminals.
U.S. Patent Application Publication No. 2012/0089141 to Lee et al. discloses an electrode body which is flexible and includes a first electrode, an insulator, and a second electrode. A process is disclosed including detecting a nerve responsible for pain and ablation of tissue with electrocautery.
U.S. Pat. No. 7,693,562 to Marino et al. discloses a probe which includes electrodes which may detect an EMG response to detect a nerve.
In U.S. Patent Application Publication No. 2010/0152726 to Cadouri et al., an electrosurgical system with selective control of active and return electrodes is disclosed. The electrosurgical system comprises a wand and a controller. The controller comprises a non-conductive outer surface, at least three electrodes disposed on a distal end of the wand and at least three electrical leads extending from a proximal end of the wand. A control circuit is configured to selectively activate the electrodes.